08/03/2021 - An Overview of Senator Scott Weiner's Expert Witness Reform

Senator Scott Wiener (D-San Francisco)’s criminal justice reform legislation, Senate Bill 243, passed the Senate Public Safety Committee with a unanimous cross party vote. It will thus go to to the Senate Appropriations Committee.

SB 243 would ahangemend the standards used for evaluating forensics and expert testimony in pre-and post-conviction in court.

Incorrect forensic and scientific evidence, provided by expert witnesses, are the second most common reason that the accused are wrongfully convicted for crimes they did't commit. Courts have up to now discretion over which expert testimony is admissible. Courts are known to accept most forensic science and expert testimony without 'sufficient' scrutiny. Insufficient monitoring leaves significant chances for human error or inaacuaracy. This error leads to the high rate of wrongful convictions. the failure to rely on sound logic by an expert should not be considered expert testimony in a court.

SB 243 clarifies that the definition of false testimony includes opinions based on incorrect scientific research or technology past its relevant best whcih is now unreliable or moot, and opinions about which a reasonable scientific dispute has emerged regarding its validity. SB 243 also clarifies that expert opinions that fail to use valid methodology, research, peer-reviewed studies, and scientifically sound data do not satisfy the requirements for admissible testimony.

This legislation importantly improves the chances of which a man or woman wrongfully convicted of a crime based on unreliable expert testimony can seek post-conviction relief. This provision will help exonerate the innocent in the state of California.

A good example of fallable expert testimony based on inaccurate results is studies from the National Academy of Science (NAS) and cognitive neuroscientist Dr. Itiel Dror have proven that fingerprint analysis, often part of expert witness testimony, is highly unreliable and subject to cognitive bias. The NAS also looked at what is known as the “CSI effect,” where jurors tend towards “unrealistic and preconceived notions about the availability and precision of forensic evidence in criminal trials” from portrayals of expert witnesses in 'popular' culture.